While radio observations are suitable to constrain the high energy part of the relativistic electrons spectrum and the magnetic field, they are not able to provide information on the low energy part of the electrons spectrum, and on the thermal gas inside the cavity. The Sunyaev-Zel'dovich effect (SZE) produced inside the cavity, i.e. the distortion of the Cosmic Microwave Background (CMB) spectrum by inverse Compton scattering (ICS) [1]}, has instead been proposed as a probe to constrain the low energy electrons or the thermal gas properties [2]}, [3]}, [4]}. With this kind of information it is possible to constrain the energetic content of the different components inside the cavity, because the low energy part of the electrons spectrum is the dominant one in determining the total energy stored in them [5]}.
